<!DOCTYPE html>
<title>Prerendered iframe</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<body>
<script>
assert_true(document.prerendering);

const bc = new BroadcastChannel('iframe-channel');
bc.postMessage('prerender success');
bc.close();
</script>
</body>
